CHAPTER IV. 



ON THE ASSIMILATION OF MATTER BY PLANTS. 



The consideration of the phenomena to 

 which this subject will give rise, extends over 

 a wide field of inquiry, and will embrace the 

 consideration of every substance, which in any 

 way either forms a part of the vegetable struc- 

 ture itself, or which serves as a means of con- 

 veying or affording such matter to plants. 



In pursuing this subject, many facts may be 

 communicated to those whose attention has 

 not been turned to this inquiry, which may 

 seem almost beyond the range of credibility; 

 but as nothing will be stated which cannot be 

 vouched for, on the testimony of the first 

 authorities on such subjects, the most complete 

 reliance may be placed on the information it 

 affords ; and if, in the discussion to which this 

 article may give rise, the attention of other 

 parties, better qualified, both by their abilities 

 and the opportunities which they may have 

 of verifying the results, is called to this subject 

 much good will ensue. Truth will be elicited, 

 and society must thereby derive a substantial 

 benefit. 



In the chapter on the structure of plants, it 

 has been stated that the spongelets of the roots 



